Standard electronic keyboards for computers are operated by both hands. These keyboards are too large and cumbersome for use with miniaturized hand held computers and computer terminals. Small keyboards have been developed for use with hand held computers and computer terminals. Many of these terminals are designed to be operated by the index finger of one hand. Operation by one finger is relatively slow. The large number of keys to be operated by one finger generally requires visual observation of the keyboard in order to direct the finger to the proper keys.
Keyboards designed to be operated by the thumb and four fingers of one hand have been designed to provide increased speed and to allow manipulation of the keys without visual reference to the keyboard. These keyboards are only marginally successful. It can be difficult to locate and press one key at a time. Rocker type switches, which have been used to assist the finger in locating the keys, move sideways as well as vertically. The movement to the side and the relatively short vertical movement provide poor tactile response to the fingers and slows operation.